Alkali metal salts of ethylene-acrylic acid interpolymers



Oct. 14,1969

IOOO

A. T. WALTE R ETAL 3, 7 ,825

ALKALI METAL SALTS 0F ETHYLENE-ACRYLIC ACID INTERPOLYMERS Original Filed Dec. 24. 1964 ETHYLENE- ACRYLIC ACID INTERPOLYMER SODIUM SALTS END use APPLICATION AREA PROFILE WATER SOLUBLE WATER INSOLUBLE I IX 1 I I I I I I l I l I I \I l I l l2l4 I618 |2224252B |32343638l 15254 20 v v so 40 50 ,WT. SODIUM 'ACRYLATE IN INTERPOLYMER SALT INVENTORS NDREW T. WALTER EORGE M. BRYANT "ESTER L. PURCELL "MFQaw-e A T TORNE'V United States Patent U.S. Cl. 260-881 6 Claims ABSTRACT OF THE DISCLOSURE Water soluble alkali metal salts of interpolymers of ethylene and acrylic acid having 3 to 4 carbon atoms have been found useful as textile size compositions. The base interpolymers have a melt index of about 15 to 1000 dg./min. and contain about 12 to 50% by weight of an acrylic acid interpolymerized therein. The acrylic acid alkali metal salt moieties constitute about 12 to 55% by weight of the total interpolymer salt.

This is a division of United States Ser. No. 421,160 filed on Dec. 24, 1964 now US. Patent 3,321,819.

This invention relates to alkali metal salts of ethyleneacrylic acid interpolymers and more particularly to recoverable textile warp sizes made therefrom.

A warp size is a chemical applied to the yarn comprising a warp for the purpose of protecting the yarn during subsequent handling and weaving. In these operations the yarns running in the warp direction are subjected to considerable abrasion from guide surfaces of split rods, drop wires, heddles, reed, shuttle and adjacent yarns. On a staple yarn such as cotton, the size coats the yarns, protects it against abrasion and covers up such warp defects as knots, crossed ends, slubs, and weak spots which occur in the normal variation of textile production. This is accomplished as a result of the gluing down of protruding fibers, and the abrasion resistance of the coating. On a filament yarn the size coats the yarn and cements the filaments together to form nearly a monofil, thus preventing chafing between filaments and between the yarn and guide surfaces.

A size is used to form, on the surface of a yarn, a coating or film which can withstand the abrasion occurring during slashing and weaving. In slashing the size solution is applied to a sheet of yarn, and dried on steam-heated rolls. It is necessary, as the sheet of yarn leaves the last drying roll, to separate or split each end of yarn. This is done by a series of bars. As this point in order to separate the ends without tearing the size from the yarn, the size film connecting the yarns in the sheet should have a lower cohesive strength than adhesive strength for the yarn. The size should then regain strength after splitting to form a tough abrasion-resistant coating. Moreover, in order to protect a warp against abrasion, a size must adhere to the yarn without scaling off during slashing and Weaving.

In a textile mill slashing operation, it is not uncommon to prepare batches of size and then hold them in a heated state for extended periods of time prior to slashing. The

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size in question must, therefore, be stable to shear degradation which may occur between the mixer blades and the kettle baflles. During the actual slashing operation a large amount of air is pulled into the hot size solution by the incoming yarn. It is, therefore, necessary that the size solution be stable to aeration and exhibit low viscosity loss in this phase.

A size should be stable to heat (at least up to 120 C.), oxidation and aging. No change in solubility should occur as the result of drying the size on yarn up to 100 C.

Since most present-day weave rooms are run .at high relative humidities, it is necessary that the size film remain non-tacky at humidities up to normally found in Weave rooms. A tacky material would cause size buildup on drop wires, heddles, reed and shuttle. A material which can become tacky is not acceptable.

Another instance of tackiness is the tendency of some sizing materials, to bond together when a sized warp is stored. Such a warp is lost because it is impractical to unwind it.

A third instance of tackiness is sometimes observed where the sized yarn comes in contact with a drying roll. A tacky size will leave an excessive amount of deposit on the roll.

A size should be soluble or dispersible in water up to about 15% and also be easily removable after Weaving, preferably by rinsing in water.

In the past, textiles have been sized with various agents such as, starch, gelatin, polyvinyl alcohol and the like. However, none of these compounds have been able to provide all the desired properties described above. They are subject to biological oxidation and degradation and each has specific shortcomings. For example, starch while a good size for cotton is of no value for synthetic fibers. Some sizes are useful on filament yarns but not on staple yarns, or vice versa. Of late, one of their most serious defects has become increasingly critical and that is the difiiculty of removing them from Waste water. As stream pollution increases and municipal sewage systems become more overtaxed, the need for recoverable sizes has become urgent. A size which is reusable as well as recoverable is obviously of even greater commercial interest in the textile industry.

It is, therefore, an object of this invention to provide a textile warp size which can be applied from an aqueous solution to the textile fibers of both filament and staple yarn, have suificient adhesion thereto and physical strength to protect the fibers during weaving and slashing operations and be easily removable from the fibers at the end of the weaving operation by a hot water wash.

It is another object that the size be elfective on and applicable to a wide spectrum of fibers, both natural and synthetic.

It is another object that the size be recoverable from the wash water and reusable as a size.

It is another object that the aqueous size solutions be shear and thermally stable, upon aging at elevated temperatures and resist oxidative breakdown.

It is another object that the size be non-tacky at relative humidities up to about 85 Other objects of this invenion will become apparent to those skilled in the art upon examination of the description which follows.

It has now been found that water soluble alkali metal salts of ethylene-acrylic acid interpolymers said interpolymers having a melt index of about 15 dg./min. to 1000 dg./min. and containing from about 12% to 50% by weight of an acrylic acid having 3 to 4 carbon atoms interpolymerized therein, with their acrylic acid alkali metal salt moieties including both the acrylic acid anion and the metal cation comprising about 12% to 55% by weight of the total ethylene-acrylic acid interpolymer salts, are excellent recoverable textile warp sizes.

The term acrylic acid alkali metal salt moieties includes both the acrylic acid anion and metal cation.

The term acrylic acid is used herein to include acrylic acid, CH CHCOOH and methacrylic acid,

Surprisingly, these interpolymer salts readily dissolve in hot water and remain in solution when cooled to room temperature but do not readily dissolve in cold water initially. While not wishing to be bound by any one theory, this phenomenon may be explained by assuming that at room temperature the hydrophilic ionic sites of the polymeric salts are embedded within the hydrophobis coils of the polymer moiety and are not accessible to the water phase. Upon raising the temperature of the polymer salt by exposure to hot water, the polymer moieties uncoil sufficiently to expose the ionic sites to the water and solution is effected. Cooling back to room temperature would not then be expected to result in insolubilization of the polymer salt because the original coiled state of the polymer salt is a bulk property not achievable in solution. A limping analogy might be drawn between this visualization and the apparently anomalous increase in the reduced viscosity with dilution encountered in attempting to determine the intrinsic viscosity of ionic polymers of polyelectrolytes.

Thus, a novel process for warp sizing and desizing textile fibers was discovered comprising the steps of:

(a) Sizing textile fibers with an aqueous sizing solution of the above-identified Water soluble alkali metal interpolymer salt at a concentration sufficient to deposit an effective sizing amount on the fibers;

' (b) Weaving said textile fibers in to cloth; and

(c) Desizing the textile fibers in said cloth by contacting the fibers with a hot water wash in which the salt is soluble.

A further advantage of this process is that the sizing interpolymer salt can be recovered by acidifying the wash water to a pH of about 4 to 6 thereby precipitating the ethyleneacrylic acid interpolymer and then isolating the interpolymer. The interpolymer can be reconverted to salt and then reused to make fresh sizing solution. This recycling of the textile warp size not only provides a more economical sizing process than those using a non-recoverable size, but eliminates the need and cost of waste disposal and waste treatment systems.

The term sizing amount as used in the specification, including the claims, is defined as a suflicient percent by weight of dry size, based on the weight of the yarn, to effectively size said yarn. Those skilled in the textile art can readily determine the quantity of size which is satisfactory for the specific textile yarn to be used by them.

In general, the textile size described in the present invention is employed as a size for the longitudinal or warp yarns inasmuch as the traversed yarns, (woof or weft yarns) are not ordinarily sized since they are subjected to little or no abrasive action from the loom. However, if desired, both weft and Warp yarns can be treated with this textile size.

Both older fibers, such as cotton, wool, rayon and like fibers as well as the newer synthetic materials, such as, polyamide, polypropylene, polyacrylonitrile, polyvinyl chloride, acrylonitrile-vinyl chloride copolymer, polyethylene terephthalate and like fibers can be sized by this novel textile size. This size is effective on both filament and staple yarns.

The concentration of the aqueous size solution is not narrowly critical and the preferred concentration can be determined for each particular textile to be treated.

The present Weight of size on the yarn or add-on, suitably employed is governed by several additional factors, such as economic consideration, type and weight of the yarn fibers, concentration of size, the pressure on the squeeze rolls, the construction of the fabric to be woven and the like. Thus, for example, when weaving cloth with cotton yarn, it is preferred to use aqueous solutions containing up to 15% by weight of size and to obtain an add-on of up to about 14% size on the yarn. However, higher concentrations of size and higher add-on can be employed, if desired.

Ethylene-acrylic acid interpolymer alkali metal salts can be categorized into three classes by physical characteristics, viz., structural, breathable (but water-insoluble) and water-soluble. These characteristics are determined by a combination of several variables including melt index and composition of the parent ethylene-acrylic interpolymer, melt index and composition of the interpolymer salt and percent neutralization of the parent interpolymer. The ethylene-acrylic acid interpolymer salts of the present invention are found in the water-soluble class.

In general, as the melt index of the interpolymer is lowered the acrylic acid salt content must be increased to obtain a water soluble interpolymer salt. Conversely, as the melt index is raise a lower interpolymer salt content is required to achieve water-solubility with the lower limit being about 12% by weight. This relationship is delineated in FIGURE 1 where the logarithm of the melt index of the starting interpolymer is plotted as the ordinate against weight percent of sodium acrylate in the interpolymer sodium salt. Lithium and potassium salts show similar plots in the ranges of about 12 to 54% and 17 to 50% respectively. FIGURE 1 also shows the requirements for breathable (insoluble) interpolymer salts and structural interpolymer salts as well as a transition or gray zone between the two. The line of demarcation between the breathable and water-soluble classes is not as sharp as that between structural and breathable class. This is understandable in the light of the nuances existing between interpolymer salts forming solutions and those forming emulsions in water as revealed by light scattering techniques discussed later. In a broad sense, the water-soluble class of salts is also breathable at ambient temperatures.

Although the suitable textile warp sizes of the present invention can be prepared from ethylene-acrylic acid in terpolymers having melt indices of about 15 dg./min. to 1000 dg./min. and containing about 12% to 55% by weight of acrylic acid interpolymerized therein, it is preferred to employ those interpolymers in the range of about 15 dg./mir1. to 700 dg./min. containing about 15% to 35% acrylic acid interpolymerized therein. It is particularly preferred to employ interpolymers in the range of about 18% to 30% acrylic acid and having melt indices of from about 200 to 500 dg./min. Furthermore, although the alkali metal salts of these interpolymers can contain from about 12% to 55 by weight of acrylic acid salt moieties, it is preferred to employ those containing about 15% to 35% salt groups.

Ethylene-acrylic acid interpolymer alkali metal salts can be prepared with varying salt contents, depending on the end use class for which it is aimed. This range extends from water-soluble completely neutralized ethyleneacrylic acid interpolymers, obtained with stoichiometric amounts of base, through water-soluble incompletely neutralized interpolymers through water sensitive and breathable (but not water-soluble) partially neutralized interpolymers to the water insensitive, lesser neutralized interpolymers (containing 8% salt or less in the interpolymer).

The term breathable interpolymers is used herein to mean those which exhibit high moisture vapor transmission and oxygen and carbon dioxide permeability. The neutralization of these ethylene-acrylic acid interpolymers can be effected by contacting them with free alkali metal, with alkali metal salts such as formates, acetates, nitrates, carbonates or bicarbonates and with alkali metal bases such as hydroxides or alkoxides. Preferred alkali metal bases are lithium hydroxide, sodium hydroxide and potassium hydroxide in solution, slurry or in the melt. For convenience, it is preferred to blend the interpolymer and base on a two-roll mill, in a Banbury mixer or with similar commercially available mixing equipment Well known in the art. The salt content of a given interpolymer can be determined by infrared analysis of a film specimen in the 5.0 to 6.0,u region. The absence of this carbonyl absorption band indicates a stoichiometric neutralization, that is, complete conversion of the acrylic acid moieties in the ethylene-acrylic acid interpolymer to acrylic acid salts.

Where less than stoichiometric amounts of base are reacted with the interpolymer, their solubility behavior in water is such that at certain levels of neutralization a change from a colloidal solution to a large particle size emulsion occurs, the specific point depending on the molecular weight (melt index) of the original ethyleneacrylic acid interpolymer and the concentration of salt moiety in the interpolymer. The point can be determined by light scattering techniques available with conventional light scattering apparatus in which a light beam is passed through a 1% solids aqueous colloidal solution or emulsion of the sample with back scattered light measured at an angle of 135 and transmitted light at an angle of 45 fiom the transmitted beam. Where the ratio of light intensity at 45 a colloidal solution is indicated whereas ratios of 1 indicate a larger particle size emulsion.

In addition to their utilization as textile warp sizes the interpolymer salts of this invention can also be used as ion exchange resins, hot water-soluble films for packaging bleaches, soaps and detergents, non-Woven fabric binder, beater additives, clay binders, paper coatings, wood coatings, printing ink base, protective finishes for leather, photographic films and emulsions, adhesives, surfactants, temporary coatings on metal, glass, ceramics, and the like.

The molecular weights of the ethylene-acrylic acid interpolymers are indicated in terms of melt index at 44 p.s.i. and 190C. in units of decigrams per minute (dg./min.) in conformity with ASTM D-l238-62T.

Other ASTM test methods employed in the present invention include the following:

Test: ASTM No. Secant modulus at 1% strain D-1530-58T Elongation D-882-56T Tensile properties D-882-56T Water absorption D-570-54T Moisture vapor transmission D-988-51T Light transmission D-1003-52 Brittleness temperature D-746-55T Izod impact strength D-256-64T Durometer hardness (D) D148457T Oxygen permeability D-l434-58 Inasmuch as the actual evaluation of textile sizes empirically in an actual weaving operation is expensive and time consuming, it is customary to subject candidate compounds to preliminary tests on a bench scale to screen out those compounds which lack desirable basic recoverable size properties such as water solubility, facile precipitation from aqueous solution, size solution stability, ease of size removal from fabric, adhesion and the like or which have undesirable size properties such as pituitousness, tackiness and the like. Candidate compounds which pass these preliminary tests are then subjected to more sophisticated tests and actual runs as sizes in a weaving operation.

The tests used for screening are described below.

The pituitousness of aqueous textile warp size solutions, which is undesirable because it results in size buildup on dry cans during slashing, is determined by squeezing a drop of size solution between the index finger and thumb. These two fingers are then pulled apart slowly and the distance at which the size splits is noted. The following ratings were then given:

Films of test sizes were prepared by pouring g. of a 10% aqueous solution onto a level 21 x 15 inch glass plate, drying at room temperature overnight followed by 10 minutes at C. The films were conditioned at 70 F. and 65% relative humidity for 24 hours.

Tackiness was determined by touch with 2 inch film squares after a minimum of 12 hours in a relative humidity of 92.5% at 25 C.

Film solubility was determined by recording the time and temperature necessary to dissolve a 1 inch square of film in a heated test tube containing 50 ml. of water.

Adhesion was determined essentially using the method outlined in the American Dyestulf Reporter 38, No. 9, page 372 (1949). Adhesion was classified as follows:

Class 1Very poorly adherent. Size film curled away from substrate.

Class 2Slightly adherent, Size film sticks to substrate but the entire size film can be lifted with gentle probing.

Class 3-Strongly adherent. Considerable work is reqired to separate the size film from the substrate.

Class 4Very strongly adherent. The size film is very difficult to separate from the substrate and comes away only where the probe enters the size film.

Ease of size removal from fabric was estimated by first raveling a 10 inch square of fabric A3 inch on each side, and drying it in a forced-air oven for 10 minutes at 100 C. and conditioning it at 70 F. and 65 relative humidity for four hours. The fabric was then padded with a 10% size solution under conditions to give 100% wet pickup. The sample fabric was dried for 10 minutes at 110 C. and then desized by rinsing in water at 90 C. for 5 minutes. The sample dried at 110 C. for 10 minutes was conditioned for four hours at 70 F. and 65% relative humidity and weighed. From this value the percent size retained was calculated.

Following the simpler screening tests varying concentrations of the aqueous sizes of the present invention were applied to 40/1 cotton and 42/1 polyethylene terephthalate-cotton using a Callaway laboratory slasher.

The various samples of yarn that had been sized on the Callaway slasher were tested on the Warp Shed Tester. This tester is an instrument designed to simulate all the actions of a loom except the laying in and beating up of the filling yarn by the shuttle and reed. The tester consists of a tension controlled let-off spool, two sets of harnesses and heddles, a reed, a beat-up motion, drop wires, and a take-up mechanism. The mechanical motion of the various parts simulates a loom operation.

The invention is further illustrated by the following examples in which all parts and percentages are by weight unless otherwise specified.

3,472,825 7 8 EXAMPLE 1 Films of the potassium salt prepared from the ethyleneacrylic acid copolymer (18% acrylic acid, 200 dg./min.

Ethylene-acryllc acid interpolymer salt preparatlon melt index) were p p y molding, casting from An ethylene-acrylic acid interpolymer (1180 g.) 0011- water at 100 C. and casting from water at 23 C. and mining 18% acrylic interpolymeriud therein and having various physical properties of these films compared with a melt index of 200 was mixed with 113 Of Solid each other and with amolded film of the parent ethylenesodium hydroxide and S g. of water in a Banbury mixer acrylic acid interpolymer. The data obtained are presented at 150 C. for twenty minutes. Complete neutralization in Table II.

TABLE II.-PHYSICAL PROPERTIES OF ETHYLENE-ACRYLIC ACID INTERPOLYMER AND POTASSIUM SALTS Chemical form... Film preparation Secant modulus p.s Tensile strength p.s.

Elongation, percent 43 Solubility:

Cold H2O (23 C.) Insoluble. Insoluble. Insoluble Film disintegrates. Hot H2O (100 C.) ..do So1uble..-. Soluble Soluble.

l Instron Tensile Tester, %l1nin. strain rate. 3 Instron Tensile Tester, 10 0%lmin. strain rate.

of the acrylic acid moiety was achieved as shown by in- Table III contains like data obtained with an ethylfrared analysis of the product. ene-acrylic acid interpolymer (27% acrylic acid, 16 melt An ethylene-acrylic acid interpolymer (100 g.) conindex) and its potassium salt.

TABLE IIL-PHYSIOAL PROPERTIES OF ETHYLENE-ACRYLIC ACID INTERPOLYMER AND POTASSIUM SALT Chemical form Acid.- Salt Salt Salt. Film preparation. Sol. cast (110 0.)... S01. cast (23 C.): Secant modulus p 31 16 780.

Insoluble Part soluble. Soluble Soluble.-- Soluble.

Tensile strength, p.s. Solubility:

Cold H1O (23 C.) Hot H20 (100 C.)-

1 Instron Tensile Tester, 10%lmin. strain rate. 2 Instron Tensile Tester, 100%/n1in. strain rate.

t-aining 18% acrylic acid interpolymerized therein and EXAMPLEZ having a melt index of 200 dg./min. was mixed with 14 g. of solid potassium hydroxide on a two roll mill for Llght Scatteflllg fiXammatiOIl 0f interpolymer salts 20 minutes at 150 C. Infrared examination of the product showed complete neutralization f the acrylic acid The solubility characteristics of various ethylene-acrylic moiety acid interpolymer potassium and sodium salts were fur- In a similar manner, using lithium hydroxide, the S lnvestlgzfied 8 SCattFImg techmqlle P lithium interpolymer salt was also made" viously described. Data indicating which salts formed col- Samples f a number f interpolymer salts prepared loidal solutions and which large particle size emulsions as ib d above were t t d f water l bilit at at 1% solids content in water are contained in Table IV 95-100 C. The results are given in Table I below. with polyvinyl alcohol and sodium chloride as controls.

TABLE IV.LIGHT SCATTERING DATA ON VARIOUS 1% SOLIDS SOLUTIONS AND EMULSIONS Equivalent oi caustic Aer-vi i; per

in lent angle polymer, Melt oi intensity Solid wt. index, acrylic 136 angle Aqueous Material percent dg./min. Salt acid intensity Form Run No 1 Ethylene acrylic acidinterpolyrnen... 12 Na 1.0 0.96 Borderline. 2..- ..do 12 140 No 1.0 0.97 D0. 3..- do.-- 13 50 K 1.0 1.2 Solution 4... 14 50 Na 1.0 1.4 Do. 5. 15 110 Ne 1.0 1.25 Do. s is 200 K 1.0 1.12 Do. 22 200 No 1.0 3.2 Do. 8. 27 16 K 1.0 2.5 Do. 9 18 200 K .25 0.02 Emulsion 10 18 200 K .50 1.1 Solution 11.- 27 16 K .50 0.76 Emulsion Control Polyvinyl AlcohoL. 2.0 Solution. Control 1% Aqueous NaCl 5. 5 Do.

TABLE I.-ETHYLENE-ACRYLIC ACID INTERPOLYMERS EXAMPLE 3 CONVERTED T0 SALTS Acrylic Melt 5 The eflect of interpolymer salt content on physical acid, index, Metal salt Water properties wt. percent dg./1nin. prepared soluble The effect of varying the amount of acrylic acid neu- 1; 28 g: tralized in the ethylene'acrylic interpolymer was demon- 13 7 K No, strated with an interpolymer having a melt index of 7 {2 58 5 $2 and containing 13% acrylic acid interpolymerized there- 15 110 Na Yes in. The physical properties including water absorption 2 238 and moisture vapor transmission of the parent copolymer 7 13 1 1, K, Na and copolymers having increasing sodium salt contents are contained in Table V.

TABLE V.EFFECT F SODIUM ACRYLATE CONTENT ON PROPERTIES OF POLYMER SODIUM SALTS Moisture Secant Water Absorption vapor modulus transat 1% Tensile Wt. Material mission, M. I., elongation, strength, Elongation, percent loss, wt. g.meter AA SA dg./m1n. p.s.1. p.s.i. percent pick-up percent 24 hr.

Polymer Salt Composition 1 Percent Percent Percent Percent neutralized C2 Run No.2

unwwm h w m nx n m w; mmwn flm e fim unmmwmmm w 3 m. a 1 M mm 0 wanuvamwh 5774B 3 44 07 .S n/. u W 00 .EVUfi A Ha u m. r ahs 0 mm Set 0 1 C 2 M 4 a a O zt 8 n 55588 D. a 7684s a r m n M 1 a mflh m 1 H 1 r 3.. w m Q m m a C r 0 1 d a .l 6, u .1 h a I O O f. tSr. ml mmum wwwwm m .rwccw m m m W 1 C g 3 6 0 l c O f 5 1 5n 5 h 00 w 888 W mmwm M n 66551 V. S .l. n 7886655137231 1 c a C y d n 4.000 2501 .0 ..4 h] t: 3627 a em 0 We ....51950. 00 41 H c xn 6 h I mil 6 G .14. 14 1 4 2 1 S P ei 0100 m t 6 u S M r 1 1 d e T. 6. Mm m Mme. m m .m n em w 5 g e u L d d 1 00005 P .V o t 0000575750 51.3.... w ..m M n M m%mu mmm mmmmwmewfifiuw m 0 an o e A e .1 EM 6 w 3 s .umm m 3 m a o N g... n I 1.... 0 s L .w 6H D mmu A 81036 E h H H w A e 177 55 00 O Wmww A 09 6 4? a WWIR we mfl w lwfiflfi %%fl8l%fi4%% 17770 0 S .i I 0 u 1 y w6 6 7 2 4-4-4 1 65158 g 6 mt n r. 7 6 M e 222245 09281 H pe R 0w 2 75394 0 6 0 6 U Tr .1 m m a E C 0 4.4.2 2.... m r l 7 s I a W. M .7 wum m h Y 0 a .1 n t .0. m 092891000 0 600 s mm L m m m w Mm m a w. m mmwmm m wmmwwmmmmwmomm 0000 n d O o f a e tet I I 1 LL5 L0 6Qw5 0 2w 0000 0 d P .1 U 0 ySH a a 888 14544 4352 322006 e t .D n 1 d E S g 1111 1 1 5 1 0 m n "m. m d eWm M 14544 P 6 C We I U m u S 6 r. .1 0 Y 6 7779 07505 .1 e I n an e n d L I.m 9 w%%9 .000 .0 T h I V 1 n f. 0 0 n 610 .20 51 P.mWP E a M A E .mfiSa 0 m 0 0 00 0 L m u s 0 P .m n H m M 4 w 0 0 .8 B t T 0 l. u C e t v.1 S t. B 7 33082 .1 bl 1 mn nb v. n 1 ...1 m m mmm m mw mm mm m 2... n m... we t I 1 m a m. mum M m o ermh M eo c p D. I B t SS 6 y PS8 02433 a e A NEW w n am h h W n 4392 6 C h A .L d O h f. .w .md 7700M037510830 11 .1 t 11C. h go v 0 n 1... 1. 1 A f mt. ie 20 96 4 v n n u se n R m r 2 3 am T. m 0 po n ah P D. M0 c n m T. o a 31510 n 1 .w m: m dwemu mw m 10KB. m m S f n n u m 0 Mb m n w a W 9 mm 37500 5m11 w9 m m m m m J rm mmu .m E mm. ween? 3% n. 1s m 4 mm m. R 71161 d t n a d C m e E 8.... v. un u 1 v. 6 mSY A mmww en E s .m n R m msm mm T to t 0 0 m7 n w w a mm w uw ma m m 0 I t .15 m n I m .Ww mr o k mm d c a W11 e 0 nmnm m vm f mm mm .W P s 1 O I H.l haye G m f V. 6608 f. 3 0 S IMwVI T I 0007777777700 e E s m a mmmmw m 1 1 1 mmm & e e p r not mum mm w q dm rmm m mm S m mm d a m on em w y mm MM eanetnmnmmnmmm E 0 e on Ut 1 m SD. 222999 =nm r n H e sm r .1 p .1 a e d b n S de P S 6 me w m wa mm IIIIIII es .1 e& s c m mu IIIIIII r l V. n n 6 .I V10 0 h e 3 a .1 t "CIF h 11 .1 mT a N fluqnnu0l234 5 12.. P T P m 12345678911111 .LC O 000 u avcimsPa R for 24 hours and 7 days were also recorded. The results are contained in Table VIII.

This interpolyrner before conditioning had an Izod impact strength of 5.8 ft. 1bs./in., excellent resistance to SAE 20 paratfin base lubricating oil, as demonstrated by I 1 Immersed 7 days in H1O at 23 C.

2 All measurements on 6-8 mil film, unless otherwise stated. a Control. 4 Film thickness, 10 mils. 5 High density (0.94) polyethylene. Low density (0.92) polyethylene.

EXAMPLE 5 Compositions representative of structural, breathable and water soluble interpolymer salts Several ethylene-acrylic acid interpolymer salts were 1 1 negilgible pick up after 7 days immersion in this oil at 23 C. and 50 C., excellent grease resistance and a brittleness temperature of l5 C. to ---20 C.

both cases, over 90% of the copolymer salt was removed from the fabric after one scouring. A second scouring removed the remaining salt size. The interpolymer was TABLE VIIL-EFFECT OF WATER ON PROPERTIES OF POLYMER SODIUM SALTS INTER- POLYMER COMPOSITION: 77.8/22.2 ETHYLENE-SODIUM ACRYLATE Ultimate Yield Secant tensile tensile modulus, strength, strength, Percent p.s.i. p.s.i. p.s.i. elongation Conditioning Experiment N 0.:

7 3, 840 3, 840 193 23 C., 50% 3.11., 24 hrs.

a. 926 3, 926 210 23 0., 50% R.H., 7 days. 1, 445 1, 067 325 35 (1,90% R.H., 24 hrs. 1, 421 1, 012 385 35 0., 90% 3.11., 7 days.

608 608 105 Immersed H10, 23 0., 24 hrs. 583 583 100 Immersed H1O, 23 0., 7 days.

EXAMPLE 7 then coagulated from the scounng baths by ad ustmg the Screening of interpolymer salt (23 sodium acrylate) Aqueous solutions of up to 20 weight percent of an ethylene-acrylic acid interpolymer sodium salt containing 23.4% sodium acrylate interpolymerized therein made by neutralizing with NaOH an ethylene-acrylic acid interpolymer having a melt index of 200 dg./-rnin. and an arcylic acid content of 18% (cf. Table VI, Run No. were prepared by heating the solid salts in water at 95-98 C. with stirring no gelling or precipitation occurred when the above solutions were cooled to room temperature. The pH of the solution was between 11 and 12.

Recoverability of these sizes from solution was demonstrated by coagulating them as the free acid by adding dilute hydrochloric acid, dilute ortho phosphoric acid or glacial acetic acid to the above salt solution until a pH of about 6 was reached.

Redissolution of the coagulated copolymer was demonstratd by addition of base such as 10% (weight) aqueous solutions of sodium or potassium hydroxide or concentrated ammonium hydroxide until a pH of about 11 was attained.

Films of the interpolymer sodium salt, cast from solution and dried at 125 C. in a forced air oven, were readily soluble in hot water with agitation. The tensile strength and percent elongation of films made from the original salt and from coagulated and redissolved salt, were about the same, viz., 1550-1925 psi. and 190% respectively.

pH to 6, by adding 3% aqueous hydrochloric acid. The coagulated interpolymer could be reconverted to a soluble salt in solution by trituration with 3% aqueous sodium hydroxide followed by dispersion in water and heating with agitation at 80 C.

EXAMPLE 8 Recoverability of coagulated ethylene-acrylic acid interpolymer To demonstrate further the feasibility of recovering the textile warp sizes of this invention, coagulation with four acids and the properties of the salts recovered thereby was investigated. Aliquots of a 10% solution of interpolymer salt prepared in Example 7 were treated with 1% solutions of hydrochloric, formic, sulfuric and acetic acids until all of the interpolymer coagulated. The coagulated interpolymers were filtered, rinsed with water three times and dried at C. in an oven. Ten gram samples of each were pasted with 20 g. of 3% NaOH, dispersed in g. of water and heated while stirring at C. until dissolved. The film properties of these recovered salts were compared with the original interpolymer salt and presented in Table IX. These results, particularly the adhesion and solubility data, show the excellent adaptability of these salts to the requirements of a textile size.

Solutions of the interpolymer salts before and after coagulation were also made using hard water, containing 1000 p.p.m. of calcium salts, which level exceeds that normally encountered in actual mill practice.

TABLE IX Film Properties 11 1 Elm- Stiff o acoagulant p salt Tenti n, ness, Solubility Adheslon 65% RH. Adhesion RH. Appearidentification solusile, permoduinwater once 1% solution tion p.s.i. cent lus 0. Mylar Glass Cellophane Mylar Glass Cellophane of film H01 10.7 1, 443 24s 11, 917 Soluble Fair--- Very good--- Very good.-- Fair"--. Good--- Very good... 01 rl a a a 5 12.2 720 79 7250 n n n n o. 11.5 841 32 14:600 Soluble do .-do .-do ..doair -d0 Do. 11.3 do Good--- Good do Good ..do....- Good Hazgi-t w e. Uncoagulated 12.5 1,172 102 15,700 do Fair ..do ..d0....-.. F ir -.do.-... Very good-.. Clearcontrol, intercolorpolymer salt. less.

80% soluble.

The desizing of interpolymer salt from a textile fabric and its coagulation from the wash bath was demonstrated as follows.

The 20% solution of interpolymer salt made above was padded onto unmercerized cotton at a wet pick up and dried at C. for 4 minutes. A dried add-on of 20% was achieved. Two sets of fabric samples were then scoured at the boil for one hour using two different baths, each having a liquor to fabric ratio of 25 to 1. One bath comprised distilled water while the other was an aqueous solution of 0.5% sodium carbonate and 0.1% Tergitol NPX (trademark for an ethoxylated nonyl phenol, nonionic detergent sold by Union Carbide Corporation). In

EXAMPLES 9-24 For polyethylene terephthalate/ cotton a sodium salt of an ethylene-acrylic acid interpolymer containing 18% acrylic acid interpolymerized therein and having a melt index of 200 dg./min. was used. This salt was prepared by completely neutralizing the parent interpolymer thus affording a salt containing 23.4% sodium acrylate and 76.6% ethylene interpolymerized therein and having a melt index of 0.01 dg./min.

The sizing materials were applied to 40/1 cotton and 42/1 polyethylene terephthalate/cotton (65 35 on a Callaway laboratory slasher, threaded with 252 ends spaced to produce a density of 84 ends per inch on the slasher. Slasher speed was yards per minute, with dry can temperatures of (1) 200 F., (2) 210 F., (3) and (4) 220 F.

Size box temperatures and solution characteristics of each material are listed in Table X.

A sample of each test warp was desized by the appropriate method of determine size add-on. A sample procedure for desizing is given below.

(1) Dry duplicate samples (3-5 grams) 4 hours at 221 F. Cool-weigh.

(2) Desize using a solution containing 2% Na CO and 2% Tergitol NPX at 212 F. for one hour.

(3) Rinse twice using running hot water (140 F.- 160 F.) for 1 /2 to 2 minutes. Follow this with a cold rinse.

(4) Dry desized yarn overnight at 221 F. Cool-weigh. The percent size is then calculated:

Weight of sized yarn=Weight of desized yarn Weight of desized yarn X 100=percent size add-on The percent water soluble content of the unsized yarn is obtained in the same manner; therefor, percent size add-on minus the percent water soluble content of unsized yarn=percent corrected size add-on.

All size add-on determinations are reported as percent corrected size add-on.

The sized yarns were treated on the Warp Shed Tester at 75 F., and 72% relative humidity. The warps were drawn in a plain weave pattern on two double-bar harnesses, and reeded 3 ends per dent in a 30 dents per inch reed. The Warp Shed Tester was operated at 200 picks per minute, 60 picks per inch.

Test samples were run for approximately 20 yards, or 47,760 picks.

The shed from each warp was collected and weighed, along with the warp. The percent shed was calculated as follows:

Weight of shed Weight of warp and shed 100=percent shed Desized weight mx 100=fiber in the shed TABLE X.SLASHING DATA.

14 The data obtained from the Warp Shed Tester, presented in Table XI indicate that the interpolyrner salts of this invention function well as a size on both cotton and polyethylene terephthalate/cotton yarn.

containing 19% sodium acrylate (derived from an ethylene-acrylic acid interpolymer containing 18% acrylic acid and having a melt index of 145 dg./min.), and a polyethylene terephthalate-cotton yarn sized with an interpolymer containing 23.4% sodium acrylate (derived from an ethylene-acrylic acid interpolymer containing 18% acrylic acid and having a melt index of 200 dg./min.) was demonstrated with a dye technique described below.

In both cases the yarns were sized in a Callaway slasher and run through the warp shed tester prior to desizing. The samples were scoured, along with unsized controls, for one hour in an aqueous bath containing 2.5% Tergitol NPX and 2% sodium carbonate (based on the weight of yarn) held near its boiling point. The scoured samples Were then rinsed in water near the boil for 5 minutes, cooled for 3 minutes, dried at 110 C. conditioned at R.H., F. and the add-ons determined.

To determine if complete desizing had taken place, one set of samples were dyed with 1 percent Latyl Brilliant Blue, 2G, a disperse dye, and a second set with 1 percent Calcodur Resin Fast Blue 3G, a direct dye. The direct dye will dye the cotton and to some extent the polyethylene terephthalate/cotton, but not the polymer salts. The disperse dye has aflinity for polyethylene terephthalate and the polymer or its salt, but not cotton. The desized cotton when dyed with the dispersed dye tinted to the same level as the control, indicating that there was little or no polymer salt present. The presence of polymer would have resulted in a darker shade. The desized cotton dyed to the same level as the control when the direct dye was applied. Both the direct and dispersed dyed desized cotton and polyethylene terephthalate/cotton samples showed dyeability equivalent to the control, indicating that the size had been removed to a level which did not aifect the dyeability of either yarn.

To further determine the desizability of polymer salt sized cotton yarns, a set of skeins of cotton yarn were padded with a solution of the polymer salt containing 19% sodium acrylate described above, at 180 F. The padded skeins were dried at 225 F., conditioned at 65 Squeeze Solution roll Size viscospressure, Solution box ity, Type Shedding lbs/linear solids, temp., Brookof at spht Add-on, inch percent F. field, cps. split rods percent Exam 1e:

9 R 23 9.37 3 Easy... Light.-... 9.4 15.6 9.37 160 3 ....do .do 12.7 23 10. 81 160 7. 2 23 10. 35 160 7.9 23 5. 64 160 3. 1 23 5.01 160 3.1 23 14. 86 160 13.7 23 14. 97 160 10. 2

Polymer salt on polyethylene terephthalatelcotton (65%/35%). b Polymer salt on cotton.

15 percent RH. and 70 F., and the dry add-n determined (see Table XII). The conditioned sized samples along with an unsized control were scoured as outlined above and the Weight loss determined. After correcting for the weight loss of the unsized cotton, the corrected add-on 1 6 ylene (73%)/acrylic acid (%)/sodiurn acrylate (22%) interpolymer having a melt index of 2.0 dg./rnin. were evaluated with polypropylene, polyethylene terephthalate, 40/ 1 polyethylene terephthalate/cottom (65%/ 35%) and polyamide filament yarns and spun Dynel (trademark for was compared W1th the dry add-0n. It 1s evident from vinyl chloride-acrylonitrile 60% /40% fiber) yarn. these figures that complete removal of the polymer salt A Callaway slasher was used to size all but the polytook place when this desizing method was used. ethylene terephthalate/ cotton yarns for which a Cocker The desizing of sized yarn with a Na CO /Tergit0l slasher was used. The latter yarns were tested on a Draper NPX bath described here is similar to the scouring meth- 1O XD loom. The warp was drawn in a plain weave pattern od currently being used in the textile industry. to produce a fabric having a construction of 120 x 60. Ap-

proximately 41 yards of fabric were woven. Data obtained TABLE E E %EE WITH NAZCOa With the Cocker slasher are presented in Table XIII.

Corrected Loom data are presented in Table IV. Dry scoured scoured The yarns sized on the Callaway slasher were tested on m addflnv the Warp Shed Tester at 75 F. and 72% relative humidpercent percent percent ity. The warps were drawn 1n a plain weave pattern on 6 9 9 4 7 0 two double-bar harnesses and reeded as shown in Table 812 1018 :4 XV which contains filament Warp Shed Tester data and 3 7 Table XVI which contains spun Dynel Warp Shed Tester U d 1 2.4

nsze Comm data. The Warp Shed Tester was operated at 200 picks 1N t 1 tt Cgrr t zh ie ad oh ie guals scoured add-on oi sized yam-scoured add-on per inmute and 60 Plcks per 1 Test Samples of apor control. proximately 20 yards or 47,760 plcks were run.

The filament Callaway Slashing data are presented in EXAMPLE 27 Table XVII and the spun Dynel Callaway slashing data Sizing solutions containing varying amounts of an ethin Table XVllI.

TABLE XIII.-COCKER SLASHING DATA Solution VISCOS- ity, Slasher Squeeze roll Solution Size box Brook- Shedding Corrected speed, pressure, 1b.] solids, temp., field Type of atthesplit add-on, yards] linear inch percent F. (ops.) split rods percent min.

15.6 13 160 4 Easy Light 14 10 TABLE XIV.POLYETHYLENE TEREgfIAHALATE COTTON (65%/35%), /1 LOOM Construction 1 Corrected Total Ends] Dent Cling Fuzz add-0n, ends dent reed Shed amount rating ball Break Knot Other percent 4, 964 3 40 Moderate to heavy 75+ 0 107 0 0 14 1 Construction 120 x 60.

TABLE XV.FILAMENT WARP SHED TESTER DATA Theoretical Construction Size Shedding Stops/20 Yards (Yarn) Type Corrected Total Ends] Dent Drop Fuzz of add-on, ends dent reed wires Heddle Reed ball Break Knot Other break percent POLYPROPYLENE 165 DENIER 20 FILAMENT T.P.I.

100 4 24 None-.. None None. 0 0 0 0 3.5 100 4 24 .-do do do 0 0 0 0 2.5

POLYETHYLENE TEREPHTHALATE 70 DENIER 34 FILAMENT 5-7 T.P.I.

100 2 None... None.... None 0 4 0 0 Clean... 2.7 100 2 50 do do ..d0 0 2 0 0 .-do. 2.6

POLYAMIDE DENIER 34 FILAMEN'I 5-7 T.P.I.

2 0 5 0 0 Clean-.. 3.3 100 2 0 7 0 ..-do- 2. 0

TABLE XVL-SPUN DYNEL WARP SHED TESTER DATA Theoretical Construction Stops/20 Yards of Yarn TABLE XVIL-FILAMENT, CALLAWAY, SLASHING DATA Solution viscosy, Size Slasher Squeeze roll Solution Size box Brook- Shedding Corrected speed, pressure, lb./ sollds, temp, field Type 01' at the add-on, yards] linear inch percent F. (cps.) split split rods percent min.

POLYPROPYLENE, 165 DENIER, 20 FILAMENT, T.P.I.

15.6 9. 74 140 4 Easy-... None.-.. 3. 15.6 7.09 140 3. 5 ..do -do 2. 5 10 POLYETHYLENE TEREPHTHALATE, 70 DENIER, 34 FILAMENT, 5-7 T.P.I.

15.6 9.74 150 4 Easy. None 2.7 10 15.6 7.09 150 3 -do -do 2.6 10

POLYAMIDE, 70 DENIER, 34 FILAMENT, 5-7 'I.P.I.

15.6 9. 64 150 4 Easy.... None 3.3 10 15.6 6. 39 150 3. 5 .-do. do 2.0 10

TABLE XVIIL-SPUN DYNEL CALLAWAY SLASHING DATA Solution viscosity, Slasher Squeeze roll Solution Size box Brook- Corrected speed, pressure, lb./ solids, temp., field Type of Shedding at add-on, yards] linear inch percent F. (cps.) split the split rods percent min.

SPUN DYN EL 15.6 9.60 150 4 Easy Moderate... 10.3 10 15.6 6.55 150 0 "d0 9.5 10

Although the invention has been described in its preferred forms with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example, and that numerous changes can be made without departing from the spirit and scope of the invention.

What is claimed is:

1. A textile size composition which readily dissolves in hot water and remains in solution when cooled to room temperature but does not readily dissolve in cold water initially and which can be recovered by acidifying to a pH of about 4 to 6, comprising a water soluble alkali metal salt of an interpolymer of ethylene and an acrylic acid having 3 to 4 carbon atoms, said interpolymer having a melt index of about to 1000 decigrams/minute and containing about 12 to 50% by weight of said acrylic acid interpolymerized therein, with the acrylic acid alkali metal salt moieties including both the acid anion and the metal cation comprising about 12 to 55% by weight of the total interpolymer salt.

2. The composition claimed in claim 1 wherein the acrylic acid is 3. The composition claimed in claim 1 wherein the acid is methacrylic acid,

CH3 OHz=il-COOH References Cited UNITED STATES PATENTS 3,264,272 8/1966 Rees 260785 3,321,819 5/1967 Walter et al. 28-72.6 3,338,729 8/1967 Rees 117138.8 3,355,319 11/1967 Rees l17l22 3,373,224 3/ 1968- Mesrobian 260857 FOREIGN PATENTS 655,298 1/1963 Canada.

JOSEPH L. SCHOFER, Primary Examiner J. C. HAIGHT, Assistant Examiner US. Cl. X.R. 

